Nicarbazin has long been sold and used as a coccidiostat for poultry. Infections by coccidia are extremely damaging to poultry in high-production facilities, and particularly to broiler chickens. Nicarbazin has been one of the most valuable coccidiostatic drugs for nearly thirty years.
Nicarbazin is not a single compound, but is a physical-chemical complex of 4,4'-dinitrocarbanilide with 2-hydroxy-4,6-dimethylpyrimidine. U.S. Pat. No. 2,731,382, of Basso and O'Neill, assigned to Merck and Company. It has been found that the particle size of nicarbazin has a great effect on its activity. Rogers, et al., Science 222, 630-32 (1983).
Accordingly, nicarbazin is always used for poultry medication in the form of a very fine powder, the particles of which range from a few tenths of a micron to a few microns in diameter. The fine particle size, which is necessary for best effect, accentuates a major processing difficulty of nicarbazin. It tends to develop strong electrostatic charges with handling. As a result, mixtures of nicarbazin with other substances tend to separate very easily, and the nicarbazin has a strong tendency to adhere to other surfaces and substances to which it is exposed.
The usual way to administer nicarbazin is in poultry feed, at a very low concentration such as 0.0125%. It is the custom to prepare a concentrated premix of animal drugs, which premix is then added to and mixed through batches of feed. Nicarbazin has caused important problems in handling because of its electrostatic properties. Mixed feed containing nicarbazin tends to separate, with the nicarbazin adhering to the walls of the equipment. As a result, the nicarbazin content of the treated feed is undesirably low, and other feed becomes contaminated with nicarbazin. Obviously, the situation is not desirable.
The present invention addresses the nicarbazin problem by providing an improved, non-separating feed premix.